1. Field of the Invention:
This invention relates to a rotary printing machine, and particularly to an interchangeable drum unit type rotary printing machine arranged to enable the interchange of a plurality of interchangeable drum units to be effected very easily.
2. Description of the Prior Art:
In an interchangeable drum unit type rotary printing machine, the time required for the interchange of an interchangeable drum unit occupies a great part in the operation for changing from the previous printing work to the next one.
The interchange work of the interchangeable drum unit in the prior art has involved such working process that a skilled worker manually draws a used interchangeable drum unit out of a printing machine, carries it up to an interchangeable drum unit set table while loaded on an interchange carriage or suspended by a winch, places the used interchangeable drum unit on the set table, subsequently transfers a new interchangeable drum unit to be used in the next printing work which has been carried to the vicinity of the printing machine by another interchange carriage or winch, and mounts the new interchangeable drum unit on the printing machine.
In the case where there are a large number of printing units as in the case of a multi-color printing machine, or the interchangeable drum unit is heavy, the manual interchange work would necessitate a lot of time and labor, thus lowering the printing work efficiency. In particular, in case where the interchangeable drum unit is very heavy, it is impossible to interchange the interchangeable drum unit manually, and further there is a possibility of endangering the life of the worker engaged in the interchanging operation.